Presented at a relatively elementary level, this introduction to the study of dissipative dynamical systems is addressed to an audience which is scientifically cultivated but not specialized in this discipline. Encompasses the analysis of all time-dependent phenomena, treating the major types of behavior or of evolution without direct reference to the material aspects. Focuses on physics and chemistry and avoids mathematical treatment. In a panorama which is coherent and accessible, it describes concretely the important dynamical phenomena and the way in which they appear in experimental reality. Covers basic vocabulary and regular periodic behavior, and goes on to apply them in analytical methods.